Best Twin-engined fighter

[RamRod]

BINGO! Knowing little but the history of the air war in WWII, I knew there was one distinctive spec in the P-38, because I like symmetry; counter props! I'm told the more negative feature of the "forked tail devil" was it's propensity for control loss in a dive. Fixed by the addition of dive brakes?
Still, just being a buff of WWII aircraft and pilots, the P-38 (right next to the F4U Corsair and Spitfire) always struck me as the stuff of romantic legend.

 

[DerAdlerIstGelandet]

"forked tail devil"

It was never actually called that by the Luftwaffe. It is just a myth...

 

[kool kitty89]

And they weren't dive-breaks or air-breaks that were fitted. They were dive recovery flaps (also used on late model P-47s) which (despite oviously adding drag) by changing the wing's center of lift, which corrected the pitch-down and allowed the elevator to function at higher mach numbers too due to reduction of the shock.

 

[drgondog]

And they weren't dive-breaks or air-breaks that were fitted. They were dive recovery flaps (also used on late model P-47s) which (despite oviously adding drag) by changing the wing's center of lift, which corrected the pitch-down and allowed the elevator to function at higher mach numbers too due to reduction of the shock.

I suspect that the sole purpose was to slow the beast down in dive and prevent the boundary layer separation which tended to blank out the horizontal stabilizer - which was primary reason for 'pitch down' characteristics of all high speed dives in those days - including me 262.

Center of lift movement aft will occur in transonic conditions but boundary layer separation and disruption of flow aft was the more serious issue for the P-38

 

[renrich]

Actually the P38 had counter rotating engines which setup canceled out the torque factor of the two engines. However the P38 did not turn very quickly in any direction since it's initial roll rate was poor. It was still probably the finest twin engined fighter in the war.

 

[kool kitty89]

But the slowing effect was secondary, the main purpose was to redirect the center of lift and reduce shock. The center of lift moved rearward (due to center of pressure issues) when nearing the mach-imit/compressibility zone (~.75 mach for the P-38 ), this caused the pitch-down behaviour.

After months of pushing NACA to provide Mach 0.75 wind tunnel speeds (and finally succeeding), the compressibility problem was revealed to be the center of lift moving back toward the tail when in high-speed airflow. The compressibility problem was solved by changing the geometry of the wing's underside when diving so as to keep lift within bounds of the top of the wing. In February 1943, quick-acting dive flaps were tried and proven by Lockheed test pilots. The dive flaps were installed outboard of the engine nacelles and in action they extended downward 35° in 1½ seconds. The flaps did not act as a speed brake, they affected the center of pressure distribution so that the wing would not lose its lift.

It sure would have been horrifying to over-dive in a P-38 w/out dive-flaps though. And I didn't know that the P-38 was the only a/c to ever shoot down another a/c in a glide!
View: https://www.youtube.com/watch?v=ITRLk9b9AcY

 

[Elvis]

Actually the P38 had counter rotating engines which setup canceled out the torque factor of the two engines. However the P38 did not turn very quickly in any direction since it's initial roll rate was poor. It was still probably the finest twin engined fighter in the war.

Quite correct and my apologies for calling them "props".
I remember the story of us giving P-38's to the Brits during the Lend Lease days.
One problem was the left side engine was the same as the right side engine, so the counter rotating effect was lost.
I guess the planes were shipped w/o superchargers, too. This (supposedly) lead to the Brits calling them "Castrated Lightning"'s.


...we were allies during the war, right? ( ).





Elvis

 

[SoD Stitch]

Quite correct and my apologies for calling them "props".
I remember the story of us giving P-38's to the Brits during the Lend Lease days.
One problem was the left side engine was the same as the right side engine, so the counter rotating effect was lost.
I guess the planes were shipped w/o superchargers, too. This (supposedly) lead to the Brits calling them "Castrated Lightning"'s.


...we were allies during the war, right? ( ).





Elvis

Believe it or not, the Brits actually requested they be shipped like that, so the blame pretty much falls in their lap. I think they were worried about reliability issues, hence no turbosuperchargers and no counter-rotating engines. Most of the "castrated Lightnings" ended up getting shipped back to the US and used in training squadrons. One has to wonder what a difference it would've made for the RAF if they had gotten "real" Lightnings instead of plain old Lockheed Model 322's.

 

[Marcel]

Believe it or not, the Brits actually requested they be shipped like that, so the blame pretty much falls in their lap. I think they were worried about reliability issues, hence no turbosuperchargers and no counter-rotating engines. Most of the "castrated Lightnings" ended up getting shipped back to the US and used in training squadrons. One has to wonder what a difference it would've made for the RAF if they had gotten "real" Lightnings instead of plain old Lockheed Model 322's.

I think it had something to do with maintenance. It's easier to be able to put any engine you have in any narcelle of the plane. Obviously it was a mistake as the performance degraded significantly.

 

[renrich]

I can see why they wanted all the engines to turn the same way. One would need twice as many spare engines(?) with the standard P38.

 

[kool kitty89]

And the main reason for the non-counter-rotating props on the Brits' Lightnings was mainly to make the props and engines interchangeable with those of the P-40s the Brits were also ordering, not for ease of maintanence iirc.

And it was the Lockheed factory that called the P-38 "castrated," note: this was even before the Brits had named it Lightning I, so it wouldn't have been called the "castrated Lightning."

"Because of its unturbosupercharged right-handed Allison engines, the Lightning I for the RAF was christened the "castrated P-38" by the factory. It turned out that this nickname was apt." see: Lightning I for RAF

 

[RamRod]

WOW! I'm impressed and have a headache at the same time.

OK, next. Why would you mess with something symmetrical and do a delete on the C.R. engines and further, the turbosuperchargers? Wouldn't that negate any reason to "import" a particular aircraft?

Go ahead. I took two extra strength Excedrines!

 

['Lil'tyger]

THE "P-38 LIGHTNING" was the best twin engined fighter of WW2!!!!!! no questions asked it had more kills then any other allied fighter in the pacific theater!!!!!!!!!!!! 8)

 

[Elvis]

...It's easier to be able to put any engine you have in any narcelle of the plane.

Maybe there was an idea to eventually put Merlin's in the nacelle's of the P's 38 and 40?

I never thought about that one before.

...good call!





Elvis

 

[kool kitty89]

The Brits quickly realized their mistake and, after only receiving a handful of Lightning I's, canceled the order in favour of Lightning Mk II's with turbos (and counter-props too iirc) but only one was built and none sent for some reason. Perhaps by then there realy was a prohibition on turbocharger exports, if so it only lasted until just after Pearl harbour.

Anione have more info on the turbocharger export ban?


And there's no way the Brits could have practically modified the P-38 to use Merlins, even Lockheed's proposal to use Merlins would have requried months just to reequip the factories with the necessary retooling and machinery, not to mention going through the extencinve structural redesign of the nacelles. Afterthough modification as such would be daunting at the vary least...

 

[FLYBOYJ]

The Brits quickly realized their mistake and, after only receiving a handful of Lightning I's, canceled the order in favour of Lightning Mk II's with turbos (and counter-props too iirc) but only one was built and none sent for some reason. Perhaps by then there realy was a prohibition on turbocharger exports, if so it only lasted until just after Pearl harbour....

Again that's wrong - as stated, the British order stretched the production line and enabled Lockheed to retain manpower on the P-38 line, this I heard from several people when I worked there.

 

[SoD Stitch]

And there's no way the Brits could have practically modified the P-38 to use Merlins, even Lockheed's proposal to use Merlins would have requried months just to reequip the factories with the necessary retooling and machinery, not to mention going through the extencinve structural redesign of the nacelles. Afterthough modification as such would be daunting at the vary least...

This is correct; Lockheed did have plans on the drawing board for re-engining the P-38 w/Merlins, but the plans went nowhere for a number of reasons, not the least of which was the necessity of completely redesigning the nacelles and the cooling system. Also, it apparently would've been much more difficult to build Merlins that rotated in the opposite direction, so the P-38 may have lost that beneficial feature if Merlins had been installed.

 

[drgondog]

THE "P-38 LIGHTNING" was the best twin engined fighter of WW2!!!!!! no questions asked it had more kills then any other allied fighter in the pacific theater!!!!!!!!!!!! 8)

Did you mean 'land based'? so as to not compare against F6F?

 

[AL Schlageter]

Did you mean 'land based'? so as to not compare against F6F?

When did the F6F get a second engine?

Now the F7F had 2 engines.

 

[drgondog]

When did the F6F get a second engine?

Now the F7F had 2 engines.

It was dumbass factor - I didn't notice 'twin engine' in his comment.. oh, well.